The present invention relates to a device which is intended to be carried by a tire and wheel assembly in order to detect revolutions of the latter. It likewise relates to a tire or a wheel carrying such a device and to a method for detecting revolutions of such an assembly.
An automotive vehicle in general comprises an odometer which permits the total distance covered by this vehicle to be known. This odometer however gives no information concerning the distance covered by each tire of the vehicle.
For example, during temporary change of tires (for example when putting on snow tires in winter) or when old worn tires are replaced, the distance displayed by the odometer no longer permits the distance actually covered by the tires to be known.
The only indication relating to the distance covered by a second-hand tire was, until a few years ago, the wear of its tread.
Tire manufacturers then had the idea of inserting a device which was integral with the tire, in the interior of the latter, and which permitted the distance covered by this tire to be known. Such devices already exist.
Amongst these devices, DE10117920 describes a magnetic field sensor which is placed on the tire and produces a signal as a function of the angular position of the tire relative to the orientation of the Earth's magnetic field.
Existing devices however have a limited lifespan because they consume a significant quantity of energy and are susceptible to vibrations.